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Title: Formation of collisional sheath in electronegative plasma with two species of positive ions

Sheath formation is investigated for electronegative plasma in presence of two species of positive ions in collisional environment. The gas under consideration is a mixture of oxygen and argon. Argon is the considered as having fixed volume and impact of collision is studied with increasing pressure of oxygen. Fluid equations are solved for three species namely, the two positive ions and a negative ion. Electrons are considered to follow Boltzmann distribution. Collision is modeled by constant mean free path model and has been used as a parameter. It has been found that collision enhances the sheath formation. The negative ion core is nearly unaffected by the presence of collision and is governed by the electric potential. The negative flux field is, however, affected by the presence of collision and shows a steady behavior in front of the wall. The two positive ions are heavily affected by the presence of collision and the modeling is such that their equilibrium densities can be estimated by solving simultaneous cubic equations.
Authors:
;  [1]
  1. Centre of Plasma Physics-Institute for Plasma Research, Sonapur, Guwahati, Assam-782402 (India)
Publication Date:
OSTI Identifier:
22408258
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physics of Plasmas; Journal Volume: 22; Journal Issue: 3; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; ANIONS; ARGON; BOLTZMANN STATISTICS; CATIONS; COLLISIONS; COMPUTERIZED SIMULATION; ELECTRIC POTENTIAL; ELECTRONS; MEAN FREE PATH; OXYGEN; PLASMA; PLASMA SHEATH